Alma already had the power to ordain priests and teachers for he had already done that among his own people (Mosiah 18:18). But if a bishop can't make changes in another's ward, then Alma did not have the stewardship to ordain priests and teachers in Zarahemla until his stewardship was expanded by Mosiah. Here we see the pattern of order and wisdom in the administration of the Lord's kingdom. The Lord spoke to Oliver Cowdery about the words of the Book of Mormon which he had been writing and explained that in them are all things written concerning the foundation of my church, my gospel, and my rock (DC 18:4). Alma's ministry is a good example of the importance of stewardship in church administration and the importance of receiving one's ordination under the hands of the Lord's authorized servants. These truths are pillars of strength in the foundation of the Lord's church.